Dolichopus sincerus Melander, 1900

Runyon, Justin B., 2022, Nematode-induced demasculinization of Nearctic Dolichopodidae (Diptera) with five new synonyms, Zootaxa 5092 (5), pp. 545-558 : 548-550

Dolichopus sincerus Melander, 1900

( Figs 13–15 , 18, 19 )

Dolichopus sincerus Melander, 1900: 3 .

Dolichopus subdirectus Van Duzee, 1921: 118 .

Dolichopus frosti Runyon, 2008: 370 , syn. nov.

Nematode. Apparent Mermithidae .

Demasculinized males examined. 4 ♂ (including holotype of Dolichopus frosti ), USA, Pennsylvania, Centre County, Black Moshannon State Park, Moss-Hanne Trail , Shirks Run , 580 m, 23 July 2006, N 40°53.396’ W78°02.584’ , muddy trail through sphagnum bog, JB Runyon; 4 ♂, same as previous, 26 July 2007 ( MTEC, PSUC, USNM) .

Remarks. Infected specimens of D. sincerus differ from normal specimens in having unusually small and incompletely rotated genitalia (cf. Figs 18, 19 ), a wider face with silver pruinosity (cf. Figs 13, 14 ), costa without or with at most indistinct enlargement at apex of R 1, abdominal sternite 2 with longer ventral hairs (similar to female), and in lacking a broad, lustrous, posterodorsal spur at apex of the hind tibia. Twenty-three normal males of D. sincerus were collected at the site with eight demasculinized male specimens.

Figures

FIGURES 7–15. Effects of mermithid-like nematode infection on faces of male Dolichopus species. Normal males (left column), infected males (middle column), and females (right column). 7–9. Dolichopus dorycerus Loew. 10–12. Dolichopus partitus Melander & Brues. 13–15. Dolichopus sincerus Melander.

FIGURES 16–19. Comparison of normal male of Dolichopus versus those infected by mermithid-like nematodes. 16. Habitus of normal Dolichopus partitus Melander & Brues. 17. Habitus of infected D. partitus. 18. Habitus of normal Dolichopus sincerus Melander. 19. Habitus of infected D. sincerus. Inset shows mermithid-like nematode removed from abdomen of D. sincerus.